Pattern type lawn sprinkler



May 20, 1958 w. D. EGLY l-:T AL

PATTERN TYPE LAWN SPRINKLER Filed July 19, 1954 I5 Sheets-Sheet 1 May20, 1958 w. D. EGLY ET AL 2,835,529

PATTERN TYPE LAWN SPRINKLER Filed July 19, 1954 Y 3 sheets-sheet 2 May20, 1958 w. D. EGLY ET Al. 2,835,529

' PATTERN TYPE LAWN SPRTNKLER Filed July 19, 1954 3 Sheets-Sheet 5 @MWJPATTERN TYPE LAWN SPRIKLER William D. Egly and Columbus Wl Harris, SouthBend, Ind., said Harris assiguor to said Egly Application July 19, 1954,Serial No. 444,062

12 Claims. (Cl. 299-18) This invention relates to sprinklers.

The primary object of this invention is to provide a lawn sprinklercapable of sprinkling a square area or other polygonal shaped area witha substantially uniform concentration of water discharge at all pointswithin the area.

A further object is to provide a lawn sprinkler having a rotatable waterreaction sprinkler for sprinkling a circular area, and a nozzle capableof discharging a stream of water a greater distance than the first namedrotatable sprinkler unit, and periodically shifted through apredetermined angular displacement by means actuated by the rotatingsprinkler unit.

A further object is toprovide a lawn sprinkler having a rotatable waterreaction sprinkler and a secondary discharge nozzle and a meansresponsive to the rotation of the first named sprinkler head forshifting said second nozzle successively to angularly displaced positionand for oscillating said secondary head in each of said positions.

A further object is to provide a device of this character having arotatable water reaction sprinkler head and a secondary sprinkler headmounted on a rotatable fitting and actuated by mechanism having adriving connection with the rotatable water reaction head and includinga cam of. irregular contour engageable by a follower having a drivingconnection with a nozzle mounting fitting so asV to oscillate saidfitting and the nozzle carried thereby, said cam and cam follower alsohaving a pin and notch driving connection for rocking said cam followerthrough a predetermined angle upon each engagement of said pin and slotincident to each full revolution of the cam.

Other objects will be apparent from the following specification.

In the drawing:

Fig. l is a side view of the sprinkler with parts shown in section takenon line l-l of Fig. 2;

Fig. 2 is an enlarged fragmentary sectional view taken on line 2--2 ofFig. l;

Fig. 3 is a transverse horizontal sectional View taken on line 3 3 ofFig. l, and illustrating the parts in one operative position;

Fig. 4 is a view similar to Fig. in a second operative position;

Fig. 5 is a view similar to Fig. in still another operative position;

Fig. 6 is a View similar to Fig. 3 illustrating the parts in anotheroperative position;

Fig. 7 is a schematic view illustrating the manner in which the deviceoperates to sprinkle a square area;

Fig. 8 is an enlarged fragmentary detail View illustrating `a modifiedembodiment of the invention, and v/ith parts shown in section; l

Eig. 9 is a sectional view taken on line 9-9 of Fig. 8;

Fig. l0 isla sectional view taken on line lil--lfl of Fig. 8; and

Fig. 1'1 is a schematic view showing the sprinkling patirnprovements inlawn 3, illustrating the parts 3, illustrating the parts tern of theembodiment of the sprinkler shown in Figs. 8, 9 and 10.

Referring to the drawings which illustrate the preferred embodiment ofthe invention, and particularly to Figs. l to 7, the numeral llldesignates a base having a frame or housing portion Il?. supported bylegs 14 extending downwardly and outwardly in divergent relation fromthe frame lll and preferably connected together in pairs by runnerportions i6. The frame portion 12 has a central downward projection 18provided with a substantially LShaped bore having a portion 20 extendingupright and a lower portion Z2. The upper end of the bore 2t)communicates with a screw-threaded socket 24 defined in an upwardlyprojecting collar portion 26. The bore portion 2.2 communicates with ascrew-threaded enlarged socket 2d receiving a tubular fitting 3l) havingan enlarged flanged outer end portion 32 serving to position theinwardly flangedannular end 3d of an internally screwthreaded couplingcollar 3o adapted for connectionwith a water supply conduit or hose at ascrew fitting on the end of that hose.

A tube 3d has a lower screw-threaded end portion d@ which is threaded inthe bore 2d of the collar 26 of the hase and extends upwardly therefrom.Atits upper end the tube Elfi mounts a casing having a base 42, sidewalls del, and a top 46. The top t6 is preferably removably mounted onthe side walls and may include a flange et), fitting around the sidewalls. The top t6 has a central opening defined by a substantiallyupturned flange Sil, here illustrated asfa substantially frusto conicalflange.

'A itting 52 has a large diameter upper end portion defined by anundercut annular groove 54 providing a marginal flange or shoulder Sewhich bears against .the top ct6 around the flange 5t). A reducedtubular neck portion 555 progects into the casing l2-fte. The upperportion 52 of the fitting has a bore till of a diameter greater'thauthe-bore of the reduced tubular portion 5S of the fittingand thisenlarged bore portion dit communicates with a mouth having an internalscrew-thread to receive and be connected to a substantially cup-shapedfittingolyin inverted positionfand having a central bore therethrough of:substantially the same diameter as the bore of the reduced neck portion5d of the fitting 52.

A'water column tube 64 fits intthe member 3S with clearance and hasanouter diameter to fit snugly in the bore of the tubular portion 5S ofthe fitting 5L* and the bore at'the upper end of the fitting o2. Thetube 3d has a bearing ring 6o in the lower end portion thereof and asimilarl bearing'ring dil .adjacent its upper end, and these bearingsserve to position the tube 6d concentrically in thetube 3ft; The tube 6dhas an enlarged annular flange 7@ at its lower endvwhich-bears againstthe lower end of the lower bearing 66: and normally provides asubstantially sealed rotatable `connection of the tube 6ft with thebase. A port 72 is preferably formed in the tube 3S between the bearingsdei and 63 to accommodate discharge of any water whicl1=might leak pastthe seal defined by the engagement of the flange bl'with the lowerbearing 6d.

The upper `end kof the tube 64 is externally screwthreaded to-mount aT-tting ".74- or a head havingtwoor more radial bores communicating with.a vertical bore communicating with the upper end of the tube '64..Later-ally extending tubular members 76 communicate with the radialbores of the head 74 and are provided with water discharge outlets. lnthe forni shown the members 76 constitute elongated tubes having bentend portions 78 4in the ends of which are mounted nozzle members 80having discharge 'apertures S2. The arms "76 are so ypositioned *thatthe water will be discharged therefrom; 'angularly, laterally andupwardly `so as lto produce a water-reaction resulting in'rotationof thearms 76 incident to the discharge of water therethrough, and suchrotation will be transmitted from the arms 76 through the head 74 to thetube 64 to cause the tube 64 to rotate relative to the base 10, the tube38, the casing 42, 46, and the fittings 52 and 62. v

An annular resilient seal 84 fits in the enlarged upper bore portion 60of the fitting 52 at the shoulder defined by the lower end of the bore60. A second annular resilient sealing member 86 is mounted in theinverted cupshaped fitting 62 at the upper end of the socket or cavitywithin said fitting. Each of the members S4 and 86 preferably is formedof rubber or synthetic rubber, and they may be members such as O-rings,although members of substantially U-shape cross-section, as shown, arepreferred, with the mouths of such U-shaped members facing each other sothat water under pressure located therebetween will serve to spread thesealing members into effective sealing engagement with the tube 64 andwith the respective fittings 52 and 62, so as to prevent the leakage ofliquid between the tube 64 and the fittings 52 and 62, respectively.

The reduced tubular end portion 58 of the fitting 52 fixedly mountsthereon a gear 88. The gear 88 meshes with a gear 90 rotatable on a studshaft 92 fixedly carried by the base 42 of the casing by means of a nut93. The gear 90 has a plurality of pins or lugs 94 projecting therefromand preferably located in equispaced relation to the axis of the gearand equispaced with relation to each other. Four lugs 94 are preferablyprovided, as in a case where the sprinkler is designed to sprinkle asquare area. It will be understood, however, that a number of pins 94employed is optional, although where the number is different than four,the same requirements for location of each of said pins substantiallyequally spaced from the center axis of the gear 90 and substantiallyequally spaced from each other exist.

A cam 96 is mounted upon the tube 64 and is fixedly anchored thereto asby means of a spline or key 98. The` cam 96 preferably constitutes asubstantially flat plate or disk-like member having a substantiallyuniform thickness and having a portion 100 of its periphery, hereillustrated as slightly less than 180 degrees in extent, of circularoutline concentric with the axis of the cam. The radius of the portion100 in relation to the spacing of the axes of the tube 64 and the studshaft 92 and in relation to the spacing of the lugs 94 from the axis ofthe shaft 92, is preferably such as to provide a slight rotativeclearance between the cam and the two adjacent lugs 94 located onopposite sides of a line connecting the axes of the tube 64 and of thestud shaft 92. Assuming that the tube 64 and the cam 96 travel in adirection of the arrow in Fig. 3, the outline of the periphery of thecam 96 in a rotational direction from the leading end of the arcuateperipheral portion 100 of the cam will be as follows: A substantiallyradial groove 102 is provided of a width greater than the width of thelugs 94 and of such a depth that when a lug 94' seats therein, asillustrated in Fig. 3, the depth of the groove 102 will fullyaccommodate it without binding in a radial direction. Continuing in arotational direction from the notch or recess 102, the periphery of thecam includes a portion 104 forming substantially a continuation of thearcuate surface 100, or of slightly greater radius that arcuate surface100, but merging with a cam indent or recess 106 whose spacing from theaxis of the cam is less than the radius of cam portion 100. Indent 106in turn merges with a cam nose 108 whose dimensions are preferably suchthat the maximum spacing of the outer surface thereof from the axis ofthe tube 64 is greater than the radius of the cam surface 100. Thesurface of the cam nose 108 in turn merges with another cam indent orrecess 110, and this in turn merges with the cam periphery 100.

The fitting 52 has a screw-threaded bore extending laterally therefromin an upwardly inclined direction, as

best seen in Fig. l, and located between the seals 84 and.

4 86. A nozzle member 112 is mounted in said bore and is provided withone or more water discharge passages 114. The tube 64 has one or moreapertures 116 therein located between the seals 84 and 86 andcommunicating with the bore in which the nozzle 112 is mounted.

In the operation of the device, assuming that it is connected to asource of water under pressure so that water enters and passes throughthe tube 64 and the arms 76 to be discharged at the nozzles 80, rotationof the arms 76 results which causes the sprinkling of a circular area,as illustrated by the dotted line 118 in Fig. 7. It will be understoodthat this rotating part of the sprinkler is substantially conventionaland preferably the sprinkler will be so constructed as to substantiallyuniformly sprinkle the area outlined by the circular dotted line 118 ofFig. 7.

The rotation of the head 76 rotates the tube 64 and this, in turn,controls the position of the nozzle 112. Thus the rotation of the tube64 rotates the cam 96 and each time the notch 102 of that cam comes intoregister with a lug 94 of the cam follower, the gear 90 of the camfollower is rotated through a predetermined arc or angle, here shown assubstantially degrees. Rotation of the gear 90 is transmitted throughthe gear 88fto the fitting 52 and controls the position of the nozzle112. Stated differently, the position of the nozzle 112 is changedstep-by-step or periodically between successive angularly displacedstations. Observe that the notched cam 96 and the cam follower with itslugs 94 seating in notch 102 somewhat resemble a Geneva motionmechanism.

The nozzle 112 is caused to oscillate laterally through an angle smallerthan the angular displacement between stations, during a portion of thetime that it dwells at each station. This oscillation is produced as aresult of the contour of the cam 96, as illustrated in Figs. 3, 4, 5 and6. As the cam 96 rotates from the position illustrated in Fig. 3,`itcarries with it the gear 90 until the pin 94 passes free of the slot 102and the adjacent trailing pin 94" rides upon or adjacent to the arcuateperipheral surface of the cam. This produces a dwell of the nozzle 112at a position to cause it to throw a stream of water outlined by dottedlines 120 in Fig. 7. The nozzle 112 will throw water a substantialdistance and outside of the area 118 sprinkled by the nozzles 80 mountedon the arms 76. When the indentation of the cam 96 contacts the pin 94",as seen in Fig. 4, the gear 90 is permitted to rock or turn slightly, asin a counter-clockwise direction as illustrated in Fig. 4. The rockingof the gear 90 is transmitted through the gear 88 and the fitting 52 tothe nozzle 112, causing it to be directed to and to sprinkle the areawithin the outline 122 in Fig'. 7, being a clockwise position, asillustrated in Fig. 7, because Fig. 7 is a schematic top plan viewwhereas Fig. 4 is a bottom plan view. Continued rotation of cam 96causes a cam' nose 108 to contact the pin 94" and to cause rocking ofthe gear 90 in a clockwise direction as viewed in Fig. 5, resulting inswinging of the nozzle to a position causing it to sprinkle the areaoutlined by the dotted line 124 in Fig. 7, assuming that the cam nosehas a maximum spacing from the axis of the tube 64 somewhat greater thanthe spacing of the circular cam surface 100 from the axis of the tube64. Continued rotation of the cam 96 causes the cam 94 to drop intofthecam depression 106 and then to ride over the cam surface 104 before thepin 94 is received in the notch 102 and advanced through thequarter-revolution to bring the next pin, in a clockwise direction asviewed in Figs. 3 to 6, into engagement with the cam surface. It will be`apparent that the number of cam noses or projections and camdepressions upon the surface of the cam may vary, so that the nozzle 112may be oscillated between the positions illustrated in dotted lines 122,124 in Fig. 7 through any desired number of times during each completerevolution of cam 96. It will be observed that the sprinkling areaoutlines 122 and 124 are of shorter length than the outline 120,resulting from the fact that the throw duce one step of movement of thenozzle 141.

assenso A.V V of nozzle M2 during movement to and from positionsl22 and124 isless than the throw of water by the nozzle 112 while it isstationary, i. e., while it rides upon the cam surface ltltl.

One factor of importance in the operation of the device is the fact thatthe sealing members S4 and 86, by their frictional engagement with thewater tube or column 64, tend to cause the fittings 52 and 62 to rotatewith the column and thereby to rotate the gears 88 and 9i). Thus, if weassume that the water column 64 is rotating in a clockwise direction, asviewed in Fig. 3, the parts 52, 62 and the gear 8S will tend to rotatein the same direction, and they will tend to rotate the gear 9|) and thelugs 9d in the opposite direction. Thus there is a normal tendency ofthe gear 9i) at alltimes to rotate in a Vcounter-clockwise direction, asviewed in Figs. 3 to 6, inclusive, and this determines which of the pins94 will engage the cam. Furthermore, it insures that the pin 9d", whichdoes engage the cam, is pressed positively thereagainst to cause it tomove to follow the cam contour and also to cause it to enter the notch102 when the cam presents the notch adjacent to or in register with saidpin.

Water discharges from the water column 64 through the apertures 116 intothe space within the littings 52 and 62 surrounding the water column,and Athereafter passes to the nozzle. The size of the nozzle fittingwill be such that the nozzle 112 is caused to throw a `stream a greaterdistance than the rotating nozzles Sil, and, consequently, to ll out thecorners of the area to be sprinkled, as schematically illustrated inFig. 7, in association with the oscillating movement between thepositions 122 and 124. lt is possible by this means to provide, at thecorner portions of the square to be sprinkled and outside of thecircular area 118, discharge of an amount of water equal toconcentration at which water.

is discharged within the area 113, so that there is substantiallyuniform concentration of water discharge throughout the entire squarearea reached by the device.

A modified embodiment of the invention is'illustrated in Figs. 8 to 1l,inclusive. ln this embodiment parts similar to those in the precedingembodiment of the invention bear the same reference numerals. The watercolumn 64 carries a gear portion 65 which may either be a gear mountedlixedly thereon or may be a portion integral with the water columndefined by cutting gear teeth in the surface of `the water column. Thegear portion 65 is located within the casing portion l2-*46 and aninternal ring gear 130 meshes with the gear 65, being held in meshingrelation thereto by a pair of rollers 132 carried by pins 134 carried inthe base 42 of the casing. The reduced tube portion 58 of the fitting 52mounts a gear 8@ meshing with thegear'9tl ias in the preferredconstruction. The gear 9i) rotates on stud shaft 92 carried by thecasing, and in turn 'carries a starv wheel 136 which may have fourpoints asshown or any other number dependent upon the shape of theareatobe sprinkled. The points 137 of the star wheel S136 are adapted toengage the outer periphery 138 of the ring gear 130. The ring gearperiphery 138 is interrupted by a notch 1d@ adapted to receive a pointof the star wheel 137 and to advance the same wheneverthe gear notch 140registers with a point 137.

The gear ratio between the gear 65 of the water column 64 and the ringgear 13@ determines the number of revolutions of the sprinkler headwhich are required to pro- It is possible by this arrangement to provideany desired ratio, and we have found that one ratio which workseectively is a four-toene ratio, that is, a ratio in which the number ofteeth on the gear 13@ is four times the number of teeth on the gearsection 65. lt will be understood that the ratio need not be one inwhich the number of teeth upon the large gear is an exact multiple ofthe number of teeth upon the small gear. Thus a very wide rangeof gear'6 ratios and operations is permissible, depending upon the requirementsandthe desired characteristics of operation of the device.

The outer periphery 13S of the ring gear may be of true cylindricalshape if a nozzle of the character il1us trated in Fig. 10 is employed.Alternatively, it will be understood that this periphery may be a camsurface comparable to the surface 10G-110 of the cam 96, in which eventit may be desired to use the pins 94 instead of the star wheel 136.

lt will be observed that the nozzle 141 illustrated in Fig. 1G is ot'substantially segmental shape with its sides diverging and with its topand bottom faces converging outwardly from its neck. The narrow arcuateend surface 142 of the nozzle 141 is provided with a series of apertures14d spaced therealong, of which a central aperture 146 is of a differentsize than the remainder, so that a greater amount of water may be throwna slightly greater distance from aperture 146 than is discharged throughany of the apertures M4. This results in the production of a pattern ofsprinkling as illustrated in Fig. 1l, wherein the nozzle 141 dischargeswater in a pattern as shown at 148, projecting outwardly beyond thecircular pattern of water discharged by the rotating sprinkler head andoutlined by the line 15).

While the preferred embodiments of the invention have been illustratedand described, it will be understood that changes may be made in theyconstruction of the device without departing from the spirit of theinvention, as long as such changes fall within the scope of the appendedclaims.

We claim:

l. A lawn sprinkler comprising a housing adapted to be connected to awater conduit, a ywater reactance sprinkler unit rotatably mounted bysaid housing, a second-sprinkler unit rotatably mounted by said housingsubstantially concentrically with said tirst unit, said sprinkler unitsdischarging water simultaneously, and a driving connection between saidsprinklers for intermittently and successively rotating the secondsprinkler relative to four angularly displaced stations in apredetermined sequence, said second unit having a larger discharge rangethan said irst unit to reach corner portions of a polygonal area to besprinkled.

2. A lawn sprinkler comprising a housing adapted to be connected to awater conduit, a water reactance sprinkler unit rotatably mounted bysaid housing, a second sprinkler unit rotatably mounted by said housingsubstantially concentrically with said lirst unit and including anozzle, said units discharging water simultaneously, and means actuated`by said water reactance unit for rotating the nozzle of said secondunit step by step and progressively between more than two predeterminedangularly displaced relative positions.

3. A lawn sprinkler comprising a housing adapted to be connected to awater conduit, a water reactance sprinkler unit rotatably mounted bysaid housing, a second sprinklerunit rotatably mounted by said housingsubstantially concentrically with said lirst unit, said unitsdischarging water simultaneously and means actuated by said waterreactance unit for intermittently rotatively advancing said second unitthrough a predetermined angle and for training said second unit at aselected limited area between successive advances thereof.

4. A lawn sprinkler comprising a housing adapted to be connected to awater conduit, a water reactance sprinkler unit rotatably mounted bysaid housing, a second sprinkler unit rotatably mounted by said housingsubstantially concentrically with said first unit, said unitsdischarging water simultaneously, means actuated by said water reactanceunit for intermittently rotatively advancing said second unit through apredetermined angle, and including a notched rotatable member carried bysaid lirst unit and a member associated with said second unit androtatably carried by said housing on an axis spaced from said notchedmember, spaced projections on said last named member engageable withsaid rotatable member and adapted to enter said notch to be advancedthereby.

5. A lawn sprinkler comprising a housing adapted to be connected to awater conduit, a water reactance sprinkler unit rotatably mounted bysaid housing, a second sprinkler unit rotatably mounted by said housingsubstantially concentrically with said first unit, and means actuated bysaid water reactance unit for intermittently rotatively advancing saidsecond unit through a predetermined angle and including a Geneva motionmechamsm.

6. A lawn sprinkler comprising a housing adapted to be connected to awater conduit, a water reactance sprinkler unit rotatably mounted bysaid housing, a second sprinkler unit rotatably mounted by said housingsubstantially concentrically with said first unit, and means actuated bysaid water reactance unit for intermittently rotatively advancing saidsecond unit through a predetermined angle, said first unit including asubstantially vertical rotatable water column, a rotatable member havinga notch therein and a driving connection with said water column, saidsecond unit including a fitting encircling a portion of said watercolumn, said water column having a water discharge aperturecommunicating with said fitting, a member rotatably carried by saidhousing on an axis spaced from said notched member and having spacedprojections successively engageable with said notched member to entersaid notch to be shifted thereby, said rotatable member having a smoothperiphery positioning a projection of said'last named member betweensuccessive engagements of said notch with said projections.

7. A lawn sprinkler comprising a housing adapted to be connected to awater conduit, a water reactance sprinkler unit rotatably mounted bysaid housing, a second sprinkler unit rotatably mounted by said housingsubstantially concentrically with said first unit, said units being inconstant communication with said conduit, and means actuated by saidwater reactance unit for intermittently rotatively advancing said secondunit through a predetermined angle, and including a rotary cam carriedby said first unit and a cam follower shiftably carried by said housingand having a driving connection with said second unit.

8. A lawn sprinkler comprising a housing adapted to be connected to awater conduit, a water reactance sprinkler unit rotatably mounted bysaid housing, a second sprinkler unit rotatably mounted by said housingsubstantially concentrically with said first unit, both unitscontinuously communicating with said conduit, and means actuated by saidwate'r reactance unit for intermittently rotatively advancing saidsecond unit through a predetermined angle, and including a rotatablemember on said first unit having a notch therein and a member connectedwith said second unit and shiftably carried by said housing to engagethe notched surface of said notched member for advance thereof uponentering said notch and dwell thereof between successive engagements ofsaid member with said notch.

9. A lawn sprinkler comprising a housing adapted to be connected to awater conduit, a waterl reactance sprinkler unit rotatably mounted bysaid housing, a second sprinkler unit rotatably mounted by said housingsubstantially concentrically with said first unit, both unitscommunicating `'continuously with said conduit, and means actuated bysaid water reactance unitfor intermittently rotatively advancing saidsecond unit through a predetermined angle, and including a rotary camcarried by said first unit and having an irregular camming surfaceinterrupted by a notch, and a cam follower shiftably carried by saidhousing and having a driving connection with said second unit, said camfollower engaging the notched camming surface of said cam.

10. A lawn sprinkler comprising a housing adapted to be connected to awater conduit, a Water reactance sprinkler unit rotatably mounted bysaid housing, a second sprinkler unit rotatably mounted by said housingsubstantially concentrically with said first unit, said unitsdischarging water simultaneously, and means actuated by said waterreactance unit for intermittently rotatively advancing said second unitthrough a predetermined angle and for laterally oscillating said secondunit through a smaller angle between said intermittent advances.

11. A lawn sprinkler comprising a housing adapted to be connected to awater conduit, a .water reactance sprinkler unit rotatably mounted bysaid housing, a second sprinkler unit mounted by said housingsubstantially concentrically with said first unit, and means actuated bysaid water reactance unit for intermittently rotatively advancing saidsecond unit through a predetermined angle, and including a pair ofjuxtaposed rotative parts, one part having spaced projections and theother part having a smooth perimetral surface engageable by saidprojections and interrupted by a notch adapted to re ceive and advance aprojection, and friction means engaging said units and normally tendingto transmit rotation from said first unit to said second unit and toposition said second unit to urge a projection of said one drivetransmitting part into engagement with the notched surface of said otherpart.

12. A lawn sprinkler comprising a housing adapted to be connected to awater conduit, a water reactance sprinkler unit rotatably mounted bysaid housing, a second sprinkler unit rotatably mounted by said housingsubstantially concentrically with said first unit, and means actuated bysaid water reactance unit for intermittently rotatively advancing saidsecond unit through a predetermined angle, and including a drive gear`on said first unit, a ring gear encircling and meshing with said drivegear and having a notched surface, a rotatable member carried by saidhousing for driving said second unit, and

spaced projections on said last named member engaging said'notchedsurface and adapted to enter said notch to be advanced thereby.

References Cited in the file of this patent UNTTED STATES PATENTS1,719,790 Van Aken July 2, 1929 1,730,248 Shaffer Oct. 1, 1929 2,021,962Marsh Nov. 26, 1935 2,459,244 Sellars Jan. 18, 1949 2,601,559 RibletJune 24, 1952

